<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>css注解使用(annotation apply)</title>

  <style>
    /* css的注解 */
    .container div {
      /* 前景色 */
      color: red;
      /* 背景颜色 */
      background-color: yellow;
      /* 字体大小 */
      font-size: 20px;
      /* 字体粗细 */
      font-weight: bold;
      /* 字体样式 */
      font-style: italic;
      /* 字体下划线 */
      text-decoration: underline;
    }
  </style>
</head>
<body>
  
  <div class="container">
    I am div class container
    <div class="box">I am div class box</div>
  </div>
</body>
</html>